New type of Heatmaps

[pa7]

New type of Heatmaps

[drupol]

Work in progress: http://pol-dev.be/heatmap/

I'm struggling to find a way to make the grid pan correctly, any help is welcome.

[pa7]

I think this can be easily done by extending heatmap.js' drawAlpha function + reducing datapoint accuracy (probably has to be done in the heatmap-openlayers implementation).
I wrote a small article about getting rid of too much datapoints by reducing accuracy, probably helpful:
http://www.patrick-wied.at/blog/data-clustering-for-a-multiuser-website-heatmap
you would have to get rid of the radial gradients (in drawAlpha), just set the opacity fillstyle and the fillRect should make it

[drupol]

No, I think the problem is more complicated (or maybe I don't get your explanations ?).

Let's stay that we want to divide the canvas by square of 20px width.

We need to find the 'distribution' of all the features into this grid.

The distribution means for me:
At row 1, column 3, we have 3 features.
At row 3, column 7, we heave 8 features,
etc etc etc
Then, once the distribution is done, we have to colorize the squares and set the right opacity according to the number of features into it.

I'm almost there with the demonstration up there, it's just that I can't find a way to make the grid pan with the layer behind it and I cannot cover the whole canvas with the grid (only when panning).

It looks easy but I don't think it is.
That kind of grid could be very helpful because it would requires less CPU, and that's interesting ! And the result is also very nice.

I'm looking forward for your reply.